Perhaps you should try some spelling variations:
thien hach » thien thanh, hien hanh
hanh trinh » hanh chinh
nhung cong » dung cong, thong cong, hang cong
hien sach » dien sach, kien sach, chieu sach
cong tan » cong tac, cong san, cong thanh
tan gian » tran gian, dan gian, van gian
gian cac » gian dan, gian cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((hien sach) or (thien hach)) - ((hanh trinh) OR (canh tranh)) va nhung cong tan gian cac~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien sach) OR (thien hach)) - ((hanh trinh) OR (canh tranh)) va nhung cong tan gian cac.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hien sach) or (thien hach)) - ((hanh trinh) OR (canh tranh)) va nhung cong tan gian cac".
• Adding a wildcard symbol may retrieve word variants: hoc ((hien sach) or (thien hach)) - ((hanh trinh) OR (canh tranh)) va nhung cong tan gian cac*.